Pressure-gas actuated electrical circuit breaker

ABSTRACT

An electrical switch of the gas blast type in which the contacts and a reversible drive mechanism therefor are admitted with pressurized gas controlled through a blast valve. A control rod extending upwardly through a columnar support mounting a storage chamber for the pressurized gas, an arc extinguishing chamber within which the contacts are closed, the blast valve and drive mechanism, is coupled to the blast valve through a system of levers and other mechanism such that when the control rod is released for upward movement, the blast valve moves automatically to its open position, the contacts are actuated to a first limit position, either closed or open, by the drive mechanism which is then reset for movement in the opposite direction, the blast valve is re-closed in readiness for the next actuation of the contacts to the other limit position, and the control rod is returned downward to its starting position.

United States Patent 1 Floessel et al.

[ Apr. 17, 1973 Inventors: Dieter Floessel, Fislisbach; Henri Clerc, Zurich, both of Switzerland Aktiengesellschalt Brown, Boveri & Cie, Baden, Switzerland Filed: Mar. 27, 1972 Appl. No.: 238,117

[73] Assignee:

[30] Foreign Application Priority Data US. Cl. ..200/148 D, 200/148 R Int. Cl. ..H0lh 33/54 Field of Search ..200/148 D, 148 B,

[56 References Cited UNITED STATES PATENTS 12/1964 Gonek et al. ..200/148 D 6/1968 Miller ..200/148 B FOREIGN PATENTS OR APPLICATIONS 1,103,007 2/1968 Great Britain ..200/148 D Primary ExaminerRobert S. Macon Attorney-Ralph E. Parker et al.

[ ABSTRACT An electrical switch of the gas blast type in which the contacts and a reversible drive mechanism therefor are admitted with pressurized gas controlled through a blast valve. A control rod extending upwardly through a columnar support mounting a storage chamber for the pressurized gas, an arc extinguishing chamber within which the contacts are closed, the blast valve and drive mechanism, is coupled to the blast valve through a system of levers and other mechanism such that when the control rod is released for upward movement, the blast valve moves automatically to its open position, the contacts are actuated to a first limit position, either closedor open, by the drive mechanism which is then reset for movement in the opposite direction, the blast valve is re-closed in readiness for the next actuation of the contacts to the other limit position, and the control rod is returned downward to its starting position.

4 Claims, 7 Drawing Figures PATENTED APR 1 71973 SHEET 1 [IF 2 3 3 o O m 0 m1 0 2/ 0/ o l 2 2 5 a 4 3 3 1 1 3 4 g 2 all 1 PATENTED APR 1 71973 SHEET 2 BF 2 Fig.4d

PRESSURE-GAS ACTUATED ELECTRICAL CIRCUIT BREAKER The present invention relates to an improved construction for an electrical switch wherein the contacts are subjected to a blast of compressed gas when switching between the closed and open position, and wherein after each blast of gas, the drive for the movable contact member of the switch is transferred, by means of a reversing mechanism, to a position of readiness for a direction of movement at the next blast of gas which is opposite to the previous direction, and in which the blast valve is designed for operation at the high voltage which the contact members carry, the switch also utilizing an insulated rod linkage which is elastically pre-stressed in its rest position for actuation of the blast valve, and a release magnet for the insulated rod linkage which is at earth potential.

Swiss Patent No. 495,625 discloses an electrical switch of the gas blast type including at least one switching point constituted by a pair of contact members located in a low-pressure contact chamber which is supplied with a blast of highly pressurized gas through a blast valve whenever the contact members are switched to the on or of position. The blast valve is constructed as a hollow slide valve while the drive for the movable contact member is transferred by means of a reversing device after each blast of gas to a position of readiness for a direction of movement of the movable contact member which, at the next gas blast is opposite to that of the previous one. Here the blast valve is located on a part of the switch structure which carries the high voltage to which the switch contacts are subjected. It is also known, from German Patent specification No. 1,225,741 which has been laid open for inspection, to employ insulated rod linkages in the construction of high-voltage switches of the gas blast type for actuating the associated blast valves designed for the high voltage, and which are maintained under an elastic pre-stressed condition in the rest position, and an actuating device designed as an electromagnetic is located, for example in the lower part of the switch structure. Here the electromagnet is de-energized, or energized, as the case may be, for opening or closing the blast valves, as a result of which the release of the switch takes place.

A primary object of the present invention is to provide an improved structure for a switch of the type above referred to which features a comparatively simple device by means of which the blast valve and the armature of the releasing magnet are controlled consistent with the position of the contact member, while, at the same time, the need for any type of auxiliary valving for switching control is eliminated.

This objective is achieved, in accordance with the invention by means of a novel lever system disposed between the blast valve and the insulated rod linkage to which the drive for the movable contact member is coupled in such a manner that after each switching operation, the blast valve is returned to its closed position and the armature of the release magnet is returned to its starting position.

The foregoing as well as other objects and advantages inherent in the invention will become more apparent from the following detailed description of a preferred embodiment when considered with the accompanying drawings wherein:

FIG. 1 is view of the improved switch structure in a central vertical section;

FIG. 2 is a detailed view of the improved lever system of the switch for actuating the blast valve, the lever system being illustrated in its upper limit position;

FIG. 3 shows, at the left half of the figure a partial section of the lever system along the section line lI in FIG. 2 and in the right half a plan view in the direction indicated by arrow A in FIG. 2; and

FIGS. 4a to 4d show in perspective four characteristic positions of the lever system for actuating the blast valve and the contact members of the switch.

With reference now to FIG. 1, the lower part of the vertically disposed switch structure, which is at earth potential, is indicated at l. The upper part of the switch which carries the high potential to which the switch contacts are subjected is generally indicated at 3 and is seen to be supported at the upper end of a hollow column 2 made from an insulating material. Included with the upper part of the switch structure is a housing 3a which forms a storage chamber or reservoir for an insulating and are extinguishing gas such as SF and which is maintained at high pressure. The lower part of housing 3a which has a tubular configuration continues downward by way of an insulating tube 3b and is sealed off at the lower end of the switch by a housing part 30 which is at earth potential. Associated with the upper part 3a of the switch housing are two other housing parts 4 which establish enclosures for two extinguishing chambers located symmetrically in relation to one another and to the right and left respectively of the insulated supporting columnar structure 2. The housing part 4 on the left side of FIG. 1 is shown in full, while the other housing part 4, located on the right side of the view has not been included in order to simplify the drawing. However, its structure is identical with the one shown on the left. Each housing part 4 which is at the same potential as the movable contact member 8 and is electrically connected with it by virtue of a path through metallic structural parts is extended laterally outward by means of a tubular insulating wall portion 5 on which is supported an electrically conductive endclosing structure 6 for the extinguishing chamber which carries the stationary contact member 7 of the switch. A terminal connection for the switch, not illustrated, is associated with the end-closure member 6. v

A drive piston for the movable contact member 8 is mounted in a reversing sleeve provided with corresponding bores, the sleeve in its turn being slidable within an outer cylinder which likewise is provided with bores. The drive for the contact member 8 to which is assigned an overall reference numeral 9 is coupled to a vertically positioned rotary hollow shaft 11 by way of a linkage 10. By means of a tubular blast valve 12 through which, in its movement to the left, by way of the bore 12a which then becomes free, a blast of gas is supplied to the housing part 4 for the purpose of effecting an opening, or closing of the contact members 7 and 8, by actuation of the drive piston for the movable contact member 8.

The blast valve 12 is linked by way of rod 13 to one arm of a double-armed lever 14, the other arm of this lever being linked by way of a rod 15 to a cross-head 16 which is affixed to the top end of a vertically disposed metallic rod 17 which extends upwardly through the hollow shaft 1 1 from the lower end of the switch and includes an intermediate section of insulating material. The axle of the double-armed lever 14 is connected by way of the cross member 18 and a forked lever 19 with the rotary hollow shaft 11. At its top end, the hollow shaft 11 carries a notched disc 20 provided with two notches in which a locking pin 21 engages by its lower portion. At the same time, the axle of double-arm lever 14 is carried at the lower end of a link 22, the upper end of link 22 being pivotally connected to a stationary support structure.

The lower end of the insulated rod 17 is connected to the armature 23 of a magnetic release which is constructed as a U-shaped permanent magnet 24. A control winding 25 wound on the magnet 24 functions when energized to produce a magnetic field which opposes and thus reduces the field produced by the permanent magnet.

The rotary hollow shaft 11, which surrounds the insulated rod 17 extends downward into the lower earthed part of the switch through an intermediate insulated tubular section 11a and there it is coupled through a linkage 26 to an actuating rod 27 for indicating and signalling the switch position. The switching mechanism operates in the following manner.

In the rest position of the switch, i.e., either with the contact members 7 and 8 open or closed, the blast valve 12 occupies its closed position as depicted in FIG. 1 but is constantly urged towards its open position, i.e., to the left, by the pressurized gas within housing 3a. The valve 12 cannot however, at this time, actually shift leftward to its open position because of a counter force applied to it by rod 13 which is urged to the right as a result of a downward pull exerted by magnet 24 on its armature 23 which is connected to the lower end of rod 17 which thereby exerts a downward pull on crosshead 16 which works through rod 15 to apply a counter-clockwise torque on double arm lever 14 to the lower arm of which the rod 13 is pivotally connected.

When, starting from the on, i.e., contacts closed position of the switch represented in FIGS. 1 and 4a, it is desired to switch the contacts to the of position, a release current pulse is sent to winding 25 of the holding magnet 24 with the result that the net magnetic flux attracting armature 23 is weakened to such an extent that the armature 23 is released thereby permitting it and rod 17 to which it is attached to rise as a result of the upward pull exerted on the latter through cross head 16, rod 15, double arm lever 14, rod 13 and blast valve 12 which now shifts leftward to its open position as depicted in FIGS. 2 and 4b. Locking pin 21 will now have been raised by cross head 16 thus to release the notched disc 20.

The piston drive 9 for the movable contact member 8 receives a blast of gas through the open valve 12 and, as a result, the contact member 8 passes through an intermediate position, shown in FIG. 40, to the final off position shown in FIG. 4d. At the same time, with movement of contact member 8 and piston drive 9 for switching off, a rotation of shaft 11 is effected by way of the linkage 10 and thereby, by way of the forked lever 19 and cross-head 18, a similar displacement of the double-armed lever 14, so that on the one hand rod 17 and armature 23 are now shifted downwardly to their initial position and, on the other hand, the blast valve 12 is returned to its closed position. In this way the switch mechanism and especially the lever system 13, 14, 15, 16, 18 and 19 are changed over from the switched-on position as shown in FIGS. 1 and 4a to the switched-off position as shown in FIG. 4d. In an analogous fashion, upon application of the next release pulse of current to the control winding 25, the switch mechanism is changed over from the switched-off position as shown in FIG. 4d to the switched-on position shown in FIGS. 1 and 4a. The compressed gas which, at any given time during the cycle of switching operations flows out of the high pressure gas system 3a, 3b and 3c into the low-pressure part 4, etc., is returned in a manner known in itself, by a suitable controlled compressor, not shown, from the low-pressure part of the switch into the high-pressure part.

We claim:

1. In an electrical switch of the gas blast type wherein a pressurized gas is utilized to actuate and blast the switch contacts the combination comprising, a hollow columnar support including at least an intermediate tubular section of insulating material, a first housing structure carried at the upper end of said columnar support, said housing structure being at the potential of the switch contacts and providing a storage chamber for the pressurized gas, a second housing structure located adjacent said first housing structure and which provides an arc extinguishing chamber in which are located a stationary contact member and a movable contact member supported for movement into and out of engagement with said stationary contact member, a drive mechanism connected to said movable contact member, said drive mechanism being actuated by a blast of said pressurized gas and including a reversing device operable after each gas blast to transfer said drive mechanism into a position of readiness for a direction of movement which at the next gas blast is opposite to that of the previous movement, a blast valve subjected continuously to the pressure of the gas within said storage chamber and which tends to displace the valve mechanism from its closed position to its open position thereby to admit the pressurized gas into said are extinguishing chamber and to said drive mechanism for said movable contact member, a release rod including at least an intermediate section of insulating material extending upwardly through said columnar support into said first housing structure, a release magnet disposed at the lower part of said columnar support, said release magnet being at earth potential and including an armature secured to the lower end of said release rod for exerting a downward pull thereon, and a lever system connected between the upper end of said release rod and said blast valve, said release rod when held by said magnet in its downward position being operable through said lever system to restrain said blast valve mechanism in its closed position, and said rod when released by said magnet for upward movement being operable through said lever system to permit said valve mechanism to move to its open position thereby to actuate said drive mechanism for said movable contact member in one direction to a limit position, and means coupling said drive mechanism with said lever system to return said blast valve mechanism to its closed position when said drive mechanism reaches a limit position and to move said release rod and armature downwardly to re-engage said magnet.

2. An electrical switch of the gas blast type as defined in claim 1 wherein said lever system comprises a double-arm lever pivotable about an axle located intermediate the arms and having one arm thereof pivotally connected to a rod secured to said blast valve mechanism and the other arm thereof pivotally connected to one end of a rod having its other end pivotally connected to a cross head secured to the top of said upwardly extending release rod, said axle for said doublearm lever being carried by the lower end of a link having its upper end pivotally connected to a stationary support structure, and wherein said means for coupling said drive mechanism with said lever system for returning said blast valve to its closed positionis constituted by a lever pivotally secured at one end to said axle and which is connected by linkage with a rotary hollow shaft surrounding said upwardly extending release rod,

said rotary hollow shaft being pivotally linked to said drive mechanism.

3. An electrical switch of the gas blast type as defined in claim 2 wherein said rotary hollow shaft carries a notched disc in which a locking pin engages to lock the disc when said drive mechanism reaches a limit position, said pin being released by said cross head during movement of said contact member.

4. An electrical switch of the gas blast type as defined in claim 2 wherein said rotary hollow shaft reaches to the lower portion of said columnar support and includes means actuated by rotation thereof in one direction or the other for respectively indicating and signalling of the position of the switch contact members. 

1. In an electrical switch of the gas blast type wherein a pressurized gas is utilized to actuate and blast the switch contacts the combination comprising, a hollow columnar support including at least an intermediate tubular section of insulating material, a first housing structure carried at the upper end of said columnar support, said housing structure being at the potential of the switch contacts and providing a storage chamber for the pressurized gas, a second housing structure located adjacent said first housing structure and which provides an arc extinguishing chamber in which are located a stationary contact member and a movable contact member supported for movement into and out of engagement with said stationary contact member, a drive mechanism connected to said movable contact member, said drive mechanism being actuated by a blast of said pressurized gas and including a reversing device operable after each gas blast to transfer said drive mechanism into a position of readiness for a direction of movement which at the next gas blast is opposite to that of the previous movement, a blast valve subjected continuously to the pressure of the gas within said storage chamber and which tends to displace the valve mechanism from its closed position to its open position thereby to admit the pressurized gas into said arc extinguishing chamber and to said drive mechanism for said movable contact member, a release rod including at least an intermediate section of insulating material extending upwardly through said columnar support into said first housing structure, a release magnet disposed at the lower part of said columnar support, said release magnet being at earth potential and including an armature secured to the lower end of said release rod for exerting a downward pull thereon, and a lever system connected between the upper end of said release rod and said blast valve, said release rod when held by said magnet in its downward position being operable through said lever system to restrain said blast valve mechanism in its closed position, and said rod when released by said magnet for upward movement being operable through said lever system to permit said valve mechanism to move to its open position thereby to actuate said drive mechanism for said movable contact member in one direction to a limit position, and means coupling said drive mechanism with said lever system to return said blast valve mechanism to its closed position when said drive mechanism reaches a limit position and to move said release rod and armature downwardly to re-engage said magnet.
 2. An electrical switch of the gas blast type as defined in claim 1 wherein said lever system comprises a double-arm lever pivotable about an axle located intermediate the arms and having one arm thereof pivotally connected to a rod secured to said blast valve mechanism and the other arm thereof pivotally connected to one end of a rod having its other end pivotally connected to a cross head secured to the top of said upwardly extending release rod, said axle for said double-arm lever being carried by the lower end of a link having its upper end pivotally connected to a stationary support structure, and wherein said means for coupling said drive mechanism with said lever system for returning said blast valve To its closed position is constituted by a lever pivotally secured at one end to said axle and which is connected by linkage with a rotary hollow shaft surrounding said upwardly extending release rod, said rotary hollow shaft being pivotally linked to said drive mechanism.
 3. An electrical switch of the gas blast type as defined in claim 2 wherein said rotary hollow shaft carries a notched disc in which a locking pin engages to lock the disc when said drive mechanism reaches a limit position, said pin being released by said cross head during movement of said contact member.
 4. An electrical switch of the gas blast type as defined in claim 2 wherein said rotary hollow shaft reaches to the lower portion of said columnar support and includes means actuated by rotation thereof in one direction or the other for respectively indicating and signalling of the position of the switch contact members. 